It is known to use a telescoping structure to vary the length of a longitudinal member, such as a table leg or the like. U.S. Pat. No. 2,831,739 describes an adjustable telescopic leg in which a spring biased bullet latch secured to an outer member selectively engages one of a series of longitudinally spaced holes in an inner member to adjust the length of the table leg. These bullet-type latches generally include a spring biased, bullet shaped post with a rounded forward end adapted to slide along a member and snap into a round hole in such member. Because of the tolerance or "slop" necessary for the functioning of bullet-type latches, such latches do not firmly grip the two members together. When used in a telescoping leg, there is a certain amount of wobble at the bullet latch.
It has also been proposed to combine a bullet-type latch with a threaded locking structure located at a right angle to the bullet latch's axis of travel. This is described in patent application Ser. No. 769,050, by Earl J. Cisler. That application, now U.S. Pat. No. 4,080,080, has a common assignee with the present application. In Ser. No. 769,050, it was discovered that inherent manufacturing tolerances caused a binding action on the bullet latch requiring very large or elongated holes for receiving the bullet latch. A very large oversize hole decreased the accuracy of length control, and the laterally elongated hole was expensive and tedious to machine.